There is no shortage of boatmen offering tours of the islands and snorkeling spots. Usually these are organized as day trips with fairly standardized itineraries at similar prices. Note that rates are likely to go up because of fast-rising fuel prices.
One tour takes clients around Isla Colón  to Swan’s Cay for bird-watching and snorkeling , stops for lunch and a swim at Boca del Drago , then stops down the west side of Isla Colón for at least one snorkeling spot, usually the popular Playa Estrella (a.k.a. Star Beach). Tours sometimes include a side trip up the Soropta Canal .
Expect to pay about US$10 per person for that last trip. Most other tours cost about US$20–25 per person. Note that clients have to pay additional per person entrance fees of US$3 for Red Frog Beach (the surrounding land is private property) and US$10 for the Cayos Zapatillas  (it’s in a national park). Red Frog Beach is the most popular beach on Bastimentos because it’s both attractive and accessible.
There are several established tour operators along the water in Bocas town offering sightseeing and snorkeling trips. Tours generally include snorkeling equipment, but it may not be in the best shape, so it’s best to bring your own if possible. The most professional operators carry emergency radios, and all should provide life jackets; be sure to check. Trips generally start midmorning and return to Bocas town before dark. Private tours are possible, but expect to pay more if your group has fewer than six people, the minimum for most tours.
Transparente Tours (Calle 3 near Avenida C, tel. 757-9915, transparentetours [at] hotmail [dot] com, www.bocas.com ) has been offering snorkeling and sightseeing boat tours for years now. (It joined forces with the competing J&J Tours a few years back, and it’s sometimes listed as J&J Transparente.) Tours start at 9:30 a.m. and return around 4:30–5:30 p.m. They include snorkeling equipment and an ice chest for any drinks/snacks guests bring.
Boteros Bocatoreños (tel. 757-9760, boterosbocas [at] yahoo [dot] com, www.bocas.com ), also called Boatmen United, is a group composed of boatmen who have organized to stay afloat amid growing competition from tour operators.
Bocas Water Sports Sports (Calle 3 and Avenida A, near the ferry dock, tel. 757-9541, www.bocaswatersports.com ) and Starfleet Scuba (Calle 1 next to the Buena Vista Bar and Grill, tel./fax 757-9630, www.starfleetscuba.com ), though primarily scuba and snorkeling outfits , also offer snorkeling trips.
Jampan Tours (Calle 1 just south of the CEFATI, tel. 757-9619) is under new management and introducing new tours, including forest walks, in addition to the usual suspects. It’s one of the few places able to offer tours of a small chocolate farm run by a couple of gringo expats who live in the Dolphin Bay area  (US$25 per person, plus a US$5 entrance fee). Sadly, the ocelot that adopted this couple has apparently gone to big-kitty heaven.
I feel more confident Jampan’s dolphin tour is less likely to terrorize the dolphins, so if you must do this tour, you may want to give these guys a try (though, as always, speak up if you think the boat is getting too close). The owners also have a 50-foot houseboat they can use for big groups.
It’s also possible to work out a deal with one of the many freelance boatmen offering “tour guide” services. However, these guys are generally not licensed. I’ve heard horror stories of drunk, reckless, or otherwise incompetent boatmen, though I’ve also had good experiences with some of them. Two boatmen I can recommend are Gallardo “Cabrioli” Livingston and Bola Smith. Ask for them at Boteros Bocatoreños. Most boatmen tend to live hand to mouth, so don’t be surprised when your tour starts with a run to fill the fuel tank.
Use caution if you go this route. Does the boatman have decent masks, snorkels, and fins? Does he have an emergency radio (unlikely) or at least a cell phone (often useless for distant destinations)?
Take a look at the boat before you seal the deal. Does it have life jackets, appear to be in good condition, and have a decent motor? (Some guidelines on horsepower: 75 hp will move you as fast as you’re likely to want to go in these little boats, while 15 hp will give you a slow-motion leisure cruise. Time estimates in this travel guide are based on a boat equipped with a 75-hp motor unless otherwise stated.)